Phase 1: Joining

sometimes when slems meet in the wild, they like to stack, and if they bond with each other, they will physically stick to one another.

Phase 2: Merging

If they really like each other (and are capable of mixing) they merge into a "jumbo slem", which is, as you'd expect, twice the size of a normal slem.

Phase 3: Feeding

Due to having two slems' in it's being, it is twice as hungry, so it needs more feeding.

If it's hunger is not satisfied, the jumbo will split into the original two slems.

Phase 4: Mixing

If they do stay jumbo long enough, they begin to mix, in which it will go into a hibernation-like state, where they begin to mix with each other for 2-3 days.

Phase 5: Slem-tosis

Once the mixing phase ends, the jumbo spots out a new born slem! And, if it's a mix it might be a hybrid slem!

Afternote:

The jumbo slem seems to have a small chance to split after this process, but out of the 5 cases of this, the parent slems stayed paired together 4 times. The one exception seemed to be due to the slems being asleep during the process and not immediately rejoining.