Sex on IUD--->????

Elle
Does anyone on the IUD actually feel the cum when it happens???? I have a friend who's on the pill who described sex without condoms as "simultaneous orgasms" but after I got the IUD (I mean condomless sex is great but--) I didn't feeeeel the cum when it came. (And I know it came when I had to sit on a towel for a little to let the fluid out....) but.... 
Anybody??? Is it normal to not feel him cum? Or what...?