How to tell him I've been faking it

I've never had an orgasm and I've never told any of my past or present partners. (except one FWB and he was determined to change it which just resulted in more faking) I dated a guy for 2 years and the sex was great - but no O. Now I've been dating a guy for about 5 months and sex is even better..... but still no luck. I know orgasm isn't often reached thru penetration. He rubs my clit for a while and it feels great but I can tell its just not going anywhere.. cue the fake orgasm. It's a routine now and happened with all of my past partners. I masturbate on my stomach just using pressure and everything is fine. Sooo help on a few things: Is it true that masturbating that way hinders my ability to orgasm with a man? (I've read that a few places) Should I try laying on my stomach while he touches me? AND my biggest current issue-- when and how do i tell him I've been faking it? I cant imagine someone springing this news on me. I think I'd be offended if i were him whether he admits it or not so i really don't want to hurt his feelings!!