Gym trainers in here
 

What's the best workout to tighten my manboobs? They're a bit loose and chicks keep playing with them.

Watch what you eat carefully and do push-ups, sit-ups every other day to begin with

do some running so they jiggle up and down. healthy food, small meals, stretch daily good 10min

push-ups! Lots and lots of them.

Dips as well

Benchpress is a good one as described in the post above :)

Build up your chest with muscle. Do incline and decline bench presses, not flat bench. Most people do flat bench wrong anyway, bouncing it off their chest and they get stronger but don't really build a lot of muscle. Also lean out a little bit and work out overall consistently.

Honestly, if you don't know what to do you should probably get a trainer.