Rihanna Poses in Pink Lingerie for Her Savage X Fenty Bridal Collection

Watch out A$AP Rocky ... looks like your girl Rihanna has marriage on the brain.

Check out these super sexy Instagram photos ... which show RiRi decked out in lingerie featured in her Savage X Fenty Bridal Collection.

Turns out the "Love on the Brain" singer is her own best saleswoman because she's just smoking hot in all these pics -- and there's a video as well to make your heart beat faster.

The clip captures Rihanna striking various poses in a bustier, thong and stockings. A$AP is one lucky dude, to say the least.

One part that stands out in the video is when RiRi squats next to a multi-tiered wedding cake, and later kicks over the cake ... which goes splat on the floor.

Could RiRi be sending signals to her longtime boyfriend A$AP, who has yet to put a ring on her finger?