It is the pairing between Skipper and Marlene in the cartoon series 'The Penguins Of Madagascar'. It takes the first part of Skipper's name 'Ski' and the last part of Marlene's name 'lene' and names smooshes both parts to form the name 'Skilene'.
Skilene is the most popular PoM pairing, because it is very easy to take the mainest protagonist of each gender and put them together, and both their personalities seem to work out and make their way towards each character perfectly. The cold, hard, military officer; the nice, welcoming, warm girl next door.
Some people insanely love the pairing, while others hate it. The people (mainly crazy fangirls) who love the pairing can see the light in it and love it just the way it is and get upset with the people who hate the pairing and the people who hate the fangirls who like the pairing. They also get excited and squeally whenever some fluff if it appears in the episodes (like in Miss Understanding and The Otter Woman).
The people who hate the pairing usually hate it because of the fangirls, who go a little too crazy over the couple, but that has been calmed down over the years.
Both types of people have really, really, passionate, one-sided views.
Either way, Skilene will still always be the pairing between Skipper and Marlene and that will how it will be for eternity.
Skilene cycles all around fanfiction.net, fanpop (look up 'pairings forum'), nick.com, deviantart.com, penguinshq.com (or sometihing like that), etc.
Some people pronounce it like 'Ski-leen' and others like 'Sky-leen' and others (this is probably the right way) 'Ske-leen'.
1. OMG The first fanfic ever to be published on fanfiction.net about Skilene, is 'Wooden Heart' by Esperata! I think.