I Think My Gf Enjoys Foreplay More Than Penetration

My girlfriend and I have great sex. However, we rarely have any penetrative sex. We mostly have oral sex and other types of foreplay. I know she’s very happy with our sex life, but I think (from her facial expressions) she really enjoys more when I finger her and rub her or eat her out than when I penetrate her. I know my size is decent, I’m not worried about that. However, I remember when we started dating (before we ever had sex) she told me she likes it when the guy’s penis is curved, but mine is not. I’m not sure if this is normal, or if my penis shape (not being curved) doesn’t give her pleasure. Any ideas? I’m kinda a beginner so I would welcome any advice or knowledge from any gender! Thanks.