<FrameLayout>
<GlSurfaceView ... />
<SpenSurfaceView ... />
</FrameLayout>
or, if you can't use resources and the layout inflater:
FrameLayout fl = // get or find frame layout
fl.addChild(yourGlSurfaceView);
fl.addChild(yourSpenSurfaceView);
The greater question is, can you not just draw to the SpenSurfaceView's surface directly? Then you don't need the second GlSurfaceView.