Depends.
The Church requires that the sexual act be completed internally, penis in vagina.
Oral sex is permitted as foreplay, but not to the point of completion. So too with anal sex, foreplay yes, completion,no.
This is why masturbation is always wrong, there can be no natural end. (Natural in the sense that nature intended sex for reproduction)
Knowingly sexual acts that cannot result in pregnancy due to age or medical condition (wife already pregnant) are entirely acceptable because the act itself is still natural.
However, even if you and your spouse are unable to conceive, for whatever reason, it is still not morally permissable to engage in nonpotentially lifegiving sexual acts, such as oral sex to the point of completion. No matter what your reproductive status is, the sex act must alway complete internally. This is because the Church’s teachings aren’t about making as many babies as possible, although that’s how it is often misunderstood. You must always give yourself fully to your spouse, that is the only way the two become one.
You are correct here. I should have been more clear.
See, this stuff can get pretty complicated.