合う => do something together N3
[合「あ」]う => To do A together/mutually N4
Secondary Verb
~こと請け合い => I guarantee ... N1
Happens next
場合(は) => in the event of; in the case that ~ N4
どうせ ... いじょう/どうせ ... からには => anyhow; in any case; at any rate; after all; no matter what N3
Necessity, obligation
~ににあわず (に似合わず ) => ~Different from N1
Evaluate
させてもらう => Allow me to do (favor) N4
Allow
ようにみせる => to look; to seem; to appear ~ N4
Consider it
どうせ (のこと) だから => Because eventually have to ... N3
Invite and advise
そうじゃありません => Not like that, Not that way N5
Confirm
どうせ => anyhow; in any case; at any rate; after all; no matter what N2
させてください/させてもらえますか/させてもらえませんか => please let me do N3