Endless sex bores couples, apparently (2,5)

'apparently' is the definition.
(I've seen this before)

'endless sex bores couples' is the wordplay.
'endless' means to remove the last letter.
'bores' means one lot of letters goes inside another (to bore something can mean to drill into it).
'couples' becomes 'items' (a couple might be called an 'item').
'sex' with its final letter taken off is 'se'.
'se' put within 'items' is 'IT SEEMS'.