There's a fine -- yet oh-so-KEY -- distinction here, and that is that FEELINGS, yes, can take months or even a couple of years to slowly return when a couple pieces, particularly if the marital trauma was particularly severe (ongoing affair, abuse, etc.). But the DECISION to work on the marriage -- to "piece" -- should be clear and unequivocal, in my opinion.
"Make the DECISION to work on our marriage with me, unencumbered by any outside third parties, and I will be patient with you about how long it takes for 'those feelings' to return" would be my position. Hell . . . that WAS my position, in my own sitch!!