Is it permissible for Catholics to attend other Christian denominations' Sunday worship services?

Is it permissible for Catholics to attend the Sunday worship services of other Christian denominations? Even if the Catholic has attended Mass, it was my understanding that it is wrong, possibly sinful, to attend other denominations worship services other than for weddings and/or funerals.

While it does not fulfill someone’s Sunday or holy day obligation, there is nothing inherently sinful about attending a worship service of another denomination. Such individuals should always do so cautiously due to differences in theology and scriptural interpretations.

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