"C-careful," Seamus breathed as Justin's nails dug into his back - but there was too much pleasure for him to actually feel any pain from it so he grinned and nipped Justin's lip in retaliation. He couldn't keep it slow now, was chasing that first tingle of a building orgasm by thrusting hard and fast, hands still on Justin's shoulder and chest. Justin's hips moved to meet his and Seamus groaned as he let one hand slide lower until he could wrap it around Justin's cock.