Imagine your OTP, naked in bed, with person A nestled on person B's lap, A's back pressed against B's chest. Person B is touching person A slowly and thoroughly, exploring every corner of their body, watching A's body intently. Person A gets more and more frustrated at the painstakingly slow pace that they have no choice but to take, melting into the slow and steadily growing pleasure until they reach their limit.  

(credit goes to imagineyourotp.tumblr.com)