My partner gave me HPV, i found out told him and we both have it. Sex hasn't changed the problem is at a molecular level. Since you have sex you both share the same strain so you can't keep re-infecting each other with it, however if one of you go out of your relationship its possible to catch other strains. At this point a condom isn't going to do anything for the strain you have. HPV can be transmitted orally, if you have done it already its probably too late. Nonetheless, sex doesn't change at least it didn't for me.
My precautions to your girlfriend ( since it effects woman much farther than men it terms of progression to cancer) is to stay on top of it and get her pap smears every 6 months. Don't let them perform surgery on you unless there high grade changes. ASCUS w/o high risk or LSIL i wouldn't jump the gun for. Also I tried these pills called Papilex, for high risk hpv, they build your immune system it started working for me until i got pregnant.
also forgot to comment that none of us has warts or any of that stuff