Women have an expectation with alpha's that such guys are able to attract many women and so will do precisely that (and if she is lucky enough to get with an alpha that being one of many is the price to be paid).

But with beta's the expectation is that their resources will be entirely at her disposal. If a beta does something to make her jealous he is somehow reneging on his part of the contract as a provider for her by squandering his resources elsewhere. Hell hath no fury like a woman scorned. The purpose of female jealousy is to prevent beta providers from becoming alpha's, to pin down a guy who might otherwise be able to build a harem.

As such, engaging with, placating or otherwise accommodating female jealousy is a shit-test and if you do it you fail.

EDIT: Thank you for the gold!