Everybody's arousal switches are different and if you are very sexually inexperienced it is common to get aroused more easily. That being said, if I have a good dance partner, doing hard body rolls into my crotch eventually I will get pretty turned on. Now onto actual advice, a lot of the time if the vibe is good and the girl is dancing sexually on you, you can turn her around and grind face to face... I like to look her in the eye and gauge interest then I whisper something like "I'm trying so hard not to kiss you right now" ...often they just smile mischievously and I go in for the makeout...I've had girls say things like "You can't resistttt" or just initiate the kiss themselves.
On the off chance that they turn away spin her back around and if she keeps dancing then give her some nice kisses on her neck...sometimes girls are sweaty, but you gotta do what you gotta do...then spin her back around and try again...if she denies you can eject, but most cave at this point...
As far as sex I'm still working on pulling from clubs/bars...a lot is logistics and getting in good with the friends so they trust you and don't think you are some creepy pervert who is going to endanger their friend. Even if you are a troll someone will benefit from this post.
