As time passes, the tension between leader and follower grows, and outside events push everything to its apex. Megatron/Starscream

Thor used to reach for Loki all the time. There came a day when he did not, so Loki reached for Thor instead.

When a suspicious Dr. is beamed aboard the Enterprise and injects Spock with a pon farr inducing drug, feelings between Captain and Commander come to light in a fierce way. Spirk slash, has elements of TOS and 2009 film

Jim chases Spock down and finds more than he expects. Slash.