Kissing was good - very good - and Barry was more than happy to let Martha pull him close, moving his own hand to rest on her thigh as he accepted her invitation and deepened their kiss, sliding his tongue into her mouth to tangle with hers. In hindsight, stripping down to his boxers may not have been his best plan, because as things heated up, it would be far more difficult to disguise his arousal, but it was too late to worry about that.
Barry certainly wasn't expecting anything more than kissing to happen, not that he would be adverse to it, and when he needed to take a break and catch his breath, he leaned his forehead against Martha's with a grin. "You are very intelligent, Dr. Jones," he teased. "Kissing certainly makes things better."
Especially since she was an excellent kisser, in Barry's limited experience.