For guys into frottage and/or intercrural sex. Very safe & very hot. No condoms needed for this kind of fun, just skin on skin.
Str8 guys not into MM anal or blowjobs should explore frottage. I can fuck a guy for 2 or 3 hrs but when he gets sore and needs me to cum fast if I can't do it from anal fast enough I flip him over and hump his cock & balls and always shoot in 2 to 3 minutes. It doesn't feel as good as having my cock in a hole, but it's more exciting mentally. But it doesn't feel bad either! Two cocks and four balls covered in baby oil and rubbing against each other is fucking hot. I've turned a lot of guys, gay & str8, on to that.
Also, if you likes guys' bodies but don't like anal try intercrural sex. Baby oil on your cock fucking between the thighs of another guy feels just as good as anal or vaj but is cleaner & safe so there is no need for a condom so it actually feels better. You really have to try it to find out how good it feels. Everyone is always amazed.