Jack actually did tense up at the give. Not hard, not dramatically, but something that made his breath fall out of rhythm, his pulse jump and made him nip sharply into the kiss. That response was there and gone in and instant and a soft growl.
From there it was a matter of finding Lane's rhythm, being able to predict the heat and stretch and slide and retreat. Once he had that again he settled down, breath evening out, pulse steadying, and moving with Lane, as much as his admittedly awkward position allowed.
Then Lane stopped, pushed inside him, deep and right fucking against his prostate. He stopped breathing, his ass tightened around Lane, and he snarled softly into the kiss. One hand went to the back of Lane's neck. Shuddering, almost shivering, panting again. Reacting hard.