Great idea. -though I have a bit of concern about it.
-Is it possible for this move/action to get abused by some users? I mean really, if someone allows the other user to be mounted (i.e pressing "Yes" to accept request) for no reason, it will be considered as a simple gateway to what they assume as 'rape'. Therefore some type of system have to be formed. Like a reason to be mounted. Probably something like so:
Player One is requesting you to be mounted for sustaining an injury.
-Something like that.
Also, "sticky pair" (what I've called it), will it form some type of lag? With so many people sticking close together (as a pair) in a group, surely there has to be an "un-sticky" option. That, or instead of using it for two creatures, why not three or more; you know for those group RP's. There's an option that can be added in the group tab. -but the group members have to be in close range or it won't work. If one person requested other group members to join in, say hunting for an example (alpha, beta, delta whatever the case may be), a few members can run over to the requester and if in range, a message would pop up. They would accept or decline the offer. Though it have to be a certain amount of people in a group, because they'll have to be in formation (similar manner in wolf packs and lion prides and etcetera) and have to be there at a certain time. Lets face it, no one likes waiting for people for them to get to point A to point B in 3 hours (more or less depending on how much it lags). They would only have to get there in a set time limit from the requester. A box would appear for the requester, stating how much time do they want to wait for the group to form up. They could type in the time or use a pre-selected time set from a list.
Example List:
1 minute
5 minutes
10 minutes
30 minutes
and so on... (max 4 hours seems fair)
If they don't reach to the requester, it's automatically denied and closed and they can't request again unless they disbanded.
-so yeah, it's kind of a mouthful, but that's what I think.