When you go to fuck your guy, you notice that he doesn't need much warming up or lube. Your dick slides in easily, almost as if something bigger has been plunging in and out of there when you're not around. This is because your man is addicted to cock and will have one shoved up his ass whenever the opportunity arises, especially not yours, especially when you're not around. Pretty much any hot guy could ask your boyfriend to bend over and he'd happily comply. Actually, knowing your slutty boyfriend it doesn't really matter how hot he is - just that he has a big cock and can shoot a big load.
02. CUM BREATH
When you go to kiss your boyfriend you can't help but notice the smell of jizz on his breathe. It's not your imagination. He swallows loads when you're not around. Yeah, even if the deal was he could play around on the side but safe, chances are he's still at least swallowing the loads of any alpha tops who tell him to. Whenever the chance arises, which he makes sure is often, he gulps down every hot load of sperm accessible to him and he loves the sensation when he can feel the balls twitch against his chin while a fat cock unloads down his throat. On the way home from work, while you're waiting for him, if he can fit in a quick load before walking in the door, he'll find it.
03. SORE KNEES
You notice he winces in pain when he's getting up or kneeling to get something. That's because when you're not around he's constantly on his knees, either sucking dick, or on all fours getting fucked. At the park, in the bushes or just in the doorway of some tricks home while he sneaks in a quick session. He likes to spend as much time as he can on his knees worshiping cock and can lose track of time in the presence of a fat prick. Your man loves servicing cock and will do it whenever he gets the chance.
04. UNDERWEAR CUM STAINS
When you do the laundry you notice tons of cum stains in his briefs. While not exclusively a sign of cheating, it typically means your man is horny all the time and you're not man enough to take care of him all the time. He's constantly fantasizing about the next cock he's going to play with - which won't be yours. Even more likely, there's some specific guy out there that's either making him leak that ball juice. As soon as you're busy, that dude is getting his load. Or it's from all the foreplay from his fucking around.
05. MARKED ASS
A sign that some alpha top is slapping his ass while pounding him. You think that fine ass of his belongs to you? Those marks are a sign that your man has another guy on the side who owns his ass when you're not around and that top couldn't give a fuck if he leaves marks and you know about it.
06. ON HIS PHONE AND DISSAPEARING.
He's on grindr finding out where there's cock nearby. And if there is cock nearby he's going to make some excuse to leave. Going for a jog? Picking up something at the store? When he excuses himself he's fucking some stranger in a bathroom stall or sucking their dick in an alley.
07. NO TROUBLE DEEPTHROATING
Your boyfriend used to have to work to take your full cock down his throat but now he seems to be able to swallow it all pretty easily. This is because some dudes with much bigger dicks have made his mouth their fuck hole and he's become accustomed to taking their big dicks. He's been complaining about a sore throat lately? That can happen when you constantly have massive pricks pounding down the back of your throat.
08.YOUR TOPS NOT UP FOR FUCKING
Guys usually feel the need to cum every couple of days and if he's not up for your ass it's because he's getting somebody elses when you're not around. That's right, that load that's meant for you is being shot up some strange willing guys mouth or asshole. That hole is new and is so much more eager to receive his cock. There's no shortage of horny bottoms who would gladly ride your mans lap and milk his cock to get every drop of his load inside of them. Everytime you've made an excuse why you weren't up for fucking he just found somebody else to drain his balls into. He likes spreading his seed into as many guys as possible.
09. HE JUST FUCKS YOU DOGGYSTYLE
He's pretending you're someone else, like that trick he fucked on your bed while you were away. With your head down on the pillows he can use his imagination to pretend you're one of your friends, that sexy waiter from the restaurant you just ate at or the cute young twink he pounded when you were out of town. Be grateful for getting his cock and don't ruin the fantasy. Keep your head down and stay quiet. If he can really get into his fantasy you might just feel the type of passion the cute guy down the street feels when your boyfriend comes over.
10. He spends a lot of time at work/library/gym/beach/park.
There's a small chance he's actually at those places, but if he is, he's most likely swapping DNA with a hot guy who isn't you. It's remarkably easy to find a random guy who's willing to get dirty with no strings attached and the venue can be somewhere easily accesible.
Did I miss anything?