Five reasons your OTP/a favourite pairing belong together.
1. Because they are so clearly in love with one another.
2. Because whilst they are wonderful alone, together they are better; they complete one another.
3. Because they are the centre of one another's world.
4. Because they complement one another.
5. Because as well as loving one another, they like one another, respect one another and would do anything for one another.
In short: just because they do :-)