Through the back door

Thommy receives an invite from her undercover sweetheart, Flame. Flame informs her that she'll have quality alone time and suggests engaging in delightfully wicked activities with no distractions. Her sole condition is that Thommy enters through the rear entrance to skirt prying eyes.
Misinterpreting the suggestion, Thommy boldly approaches Flame's taut and youthful 'back entrance', ramming in fiercely until the girl is left gaping.