The most common and most likely answer to this crossword clue is the 10 letter word FRIENDLIER
I've seen this crossword clue in The Daily Telegraph
F
R
I
E
N
D
L
I
E
R
Buddy explains!

The straight part
We know that "more affectionate" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case more affectionate = friendlier.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does FRIENDLIER mean?
FRIENDLIER adjective- Generally warm, approachable and easy to relate with in character.
- Inviting, characteristic of friendliness.
- Having an easy or accepting relationship with something.
- Without any hostility.
- Promoting the good of any person; favourable; propitious.
- Of or pertaining to friendlies (friendly noun sense 2, below). Also applied to other bipolar confrontations, such as team sports
- Being or relating to two or more natural numbers with a common abundancy.
- (in compounds) Compatible with, or not damaging to (the compounded noun).