At least I don't have to worry about Slinky losing fur from playing; she doesn't play with Scooter at all.
Sayang is very obliging towards Scooter, allowing him to play with her even when she just wants to rest - which she usually indicates by sleeping in her basket or in some corner under the TV cabinet.
I thought that Sayang didn't know how to say no to Scooter, so I tried to stop them for playing for a while, but it turns out that Sayang wants to play with him too! So, I guess I will just leave them to it.