Like Duh. Your BF is cheating! He is sneaking in play time behind your back!
It's that twi`lik tart Vette. She's talking to your BF while you are not there and giving him +10K or more exp every time. You should put the collar back on her and shock her every chance you get.
Joking aside, the amount of experience you get from talking to companions is plenty high. If he has one more companion or has been giving them the occasional gift he could easily be pulling ahead in experience gains.