Paige VanZant & Fiance Trade Punches, The Couple That Spars Together ...

UFC star Paige VanZant and her fiance spent their Tuesday punching each other in the face -- but don't worry, it was consensual.

Paige is engaged to undefeated welterweight MMA fighter Austin Vanderford -- and the two train together at a gym in Portland.

Tuesday was boxing day -- so they paired up, strapped on the gloves and let each other have it!

Paige was able to land a few shots -- so was Austin -- but when it was all said and done, there was no bad blood. In fact, PVZ suggests the workout helps them bond.

"Find someone who shares your passion and grow together ❤️ (we both signed waivers, were allowed to do this 😝)."