Guy: (To Niles who he thinks might be gay, like himself) Annie is not your... cup of tea?
Niles: (Placing his hand on Guy's knee) Just between us, my interests lie elsewhere this weekend (Winks).
Guy: (Leeringly) Oh, really.
After Guy says "Oh, really", the shot changes to catch Niles' reaction. If you look at Guy, however, you can see it is simply another perspective of him saying "Oh, really", but without sound. The editor has simply used the shot again for Niles' reaction.