Microsoft has updated the Outlook for Android app to quietly add Bing search integration to the long-press menu of Android OS itself. When you select and long-press on a text snippet, the menu will show a ''Bing search'' option along with the usual cut, copy, and web search options. This will come up irrespective of whether you have the Bing app installed on your Android phone or not. What's worse is that this "Bing search" option will show up across every app on your device and not just inside the Outlook app.
If you heavily use Microsoft apps on your Android device and use Bing for searching the web, you are going to like this integration that the company is trying to push for. If not, then the move will definitely feel spammy and intrusive. The "Bing search" option does not appear for all Outlook Android users which points to Microsoft still experimenting with it. In some cases, users were able to get rid of it by simply reinstalling the app from the Play Store
This is not the first time that Microsoft has used one of its Android apps to promote Bing. The company had previously used the Share menu and 'Open with' menu in Android to promote its apps that were not installed on a user's Android device.
Support: Pixel Support forums, Android Police