Leaning Out is a relational phrase identified by William Doherty - I am borrowing this phrase here to describe behaviors and indications that your partner is less committed than you may wish him/her to be.
Your partner/spouse is...
1) Unwilling to make future plans together (travel, large purchases)
2) Avoiding work parties or family events
3) Downplaying what used to be important dates (anniversary's, traditions, holidays)
4) Increasingly independent with money and finances
5) Seeking autonomy and time apart
6) Asserting themes about "We're different" or "We don't really know each other well."
7) Less personal disclosure of his/her daily life
8) Increased use of the unknowns, e.g., "We can't predict the future" or "We never know what might happen."
9) Your partner initiates trivial fights to create emotional distance
10) Avoids sexual intimacy