I really must commend you for wanting to have control of reproductivity. You're obviously an intelligent and either considerate or untrusting guy (either way, good for you). It's time that guys took responsibility and control into their own hands
Any relationship has to have friendship to some degree. But I see now that relationships sometimes require a complementing compatibility. A similar compatibility one might share with just friends
Tell them to cut it how YOU want it; if they cut and style, they always cut how it will look good only that day. Your hair will settle within a few days after a cut. Also, use the same products and see from what angles they dry and style; this makes a difference