How to make sex more interesting

Somme and my boyfriend have sex at least 3times a week.. it doesn't last that long like 20 minutes and we'll take breaks in between and then go back at it again .. I enjoy it but it doesn't get me to orgasm .. I want to be dirty and freaky with him, but I'm scared he's gonna think I'm a weirdo from r being too freaky and dirty.. how can I solve this... also he doesn't like talking off his shirt