From the OED
"1. trans. To be of service to; to serve; to provide with a service.
1893 R. L. Stevenson Catriona xvi. 178 If I am to service ye the way that you propose, I’ll lose my lifelihood.
1948 J. Steinbeck Russ. Jrnl. (1949) 15 Airports are so far from the cities they supposedly service.
1955 News of North (Yellowknife, N.W.T.) 18 Nov. 1/5 A new town house, available to water and sewer service, would be assessed at a much higher rate than duplicate property in a part of the town not serviced this way.
1969 D. Widgery in A. Cockburn & R. Blackburn Student Power 139 It is unlikely that a radical Executive would be able to…service the entirely different attitude of the apolitical small colleges.
1974 R. Adams Shardik lviii. 518 How many permanent camps or staging-forts would be needed to service a regular trade-route?"
The idea of service as referring to sexual acts slides in at definition #4.