Dark bra strap marks after tanning

After spray tanning topless, i get dark lines where my bra straps sit, even though i dont put a bra on after tanning, and dont put a bra on until after a shower the following day. The dark marks are from my underarms right up to the top of my sholders but no lines on my back. I exfoliate before tanning & dont wear any deoderant, moisturiser or purfumes. Please help as im getting married in March and need this resolved. Also when the tanner is first applied the darker strap marks do not apear until the following day.
Answer: Your skin must be dryer in those areas from wearing a bra for that to happen.
I would suggest either trying a Baiden Mitten which is a much deeper exfoliation, or putting a little bit of barrier cream on those areas before spray tanning. That should stop the excess of solution from penetrating the skin.